#include <bits/stdc++.h>
using namespace std;

const int siz = 9;
const string yuki = "yukicoder";

int main() {
  string s;
  cin >> s;
  int n = s.size();
  vector<int> loc;
  for (int i = 0; i <= n - siz; i++) {
    string t = s.substr(i, siz);
    if (t == yuki) {
      loc.push_back(i);
    }
  }
  int pre = 1e9;
  int cont = 0, ans = 0;
  for (int x : loc) {
    if (x - pre == siz) {
      cont++;
      ans = max(ans, cont);
    } else {
      cont = 1;
    }
    pre = x;
  }
  cout << ans << endl;
}